From the Guidelines
DIPNECH syndrome, or Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia, is a rare lung condition characterized by an abnormal proliferation of neuroendocrine cells in the airways, considered a pre-neoplastic condition that can progress to carcinoid tumors in some cases, primarily affecting middle-aged women who are non-smokers.
Key Characteristics
- DIPNECH typically presents with chronic cough, shortness of breath, and wheezing that may be mistaken for asthma or chronic obstructive pulmonary disease.
- Diagnosis requires high-resolution CT scans showing multiple small nodules and air trapping, with confirmation through lung biopsy revealing neuroendocrine cell proliferation, as noted in studies such as 1 and 1.
- The condition is generally slow-progressing but requires long-term monitoring as it can lead to progressive airway obstruction and fibrosis.
Treatment Approaches
- Observation for mild cases,
- Inhaled corticosteroids and bronchodilators for symptom management,
- Somatostatin analogs like octreotide for more severe cases, as recommended by guidelines such as 1 and 1,
- Surgical resection for localized carcinoid tumors.
Management
- Patients should be followed by pulmonologists experienced with neuroendocrine disorders for optimal management of this chronic condition.
- Treatment decisions should consider the burden of disease, symptoms, histopathology, and rate of growth, as emphasized in 1 and 1.
- Regular follow-up with chest CT scans and abdominal/pelvic multiphasic CT or MRI is essential for monitoring disease progression and adjusting treatment accordingly, as suggested in 1.
From the Research
Definition and Characteristics of DIPNECH
- Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare pulmonary condition characterized by diffuse proliferation of neuroendocrine cells in the respiratory epithelium 2, 3.
- DIPNECH lesions are typically less than 5 mm in size and are limited to the basement membrane with no invasion 2.
- The condition is considered a preinvasive lesion for carcinoid tumorlets/tumors 4, 3.
Clinical Presentation and Diagnosis
- DIPNECH often presents with chronic respiratory symptoms such as dyspnea on exertion and dry cough 2, 5.
- The condition can be difficult to diagnose, and histopathologic confirmation is usually necessary 4, 3.
- Imaging features of DIPNECH include multiple noncalcified pulmonary nodules and mosaic attenuation on CT 4.
Treatment and Management
- There is limited information on the treatment of DIPNECH, but somatostatin analogs and mechanistic target of rapamycin inhibitors have shown promise 2, 5, 4.
- Treatment is often guided by symptoms, and prognosis is highly variable 3, 6.
- Some patients may experience symptomatic improvement with treatment, including improvements in pulmonary function tests (PFTs) 5.
Epidemiology and Natural History
- DIPNECH is a rare condition that primarily affects middle-aged and elderly women 4.
- The natural history of the disease is not well understood, but it is considered to have an indolent course in most cases 4.
- Progression to overt neuroendocrine tumor (carcinoid) of the lung occurs in a minority of patients 4.